Quad operational amplifier LM324 24AEF9K E4

The LM324 (specifically the LM324A variant) is an integrated circuit containing four independent operational amplifiers (op-amps) designed to operate from a single power supply (3V to 32V) or dual supplies (±1.5V to ±16V). It is known for its low power consumption, wide bandwidth (up to 1.3 MHz), low input bias current (typically 20 nA), and low input offset voltage (typically 2 to 3 mV). Each op-amp offers high gain and a wide input voltage range, including ground, which often eliminates the need for external biasing components. The “E4” suffix typically indicates RoHS compliance and specific packaging according to the manufacturer.

The LM324 is ideal for applications requiring multiple operational amplifiers in a single package, while remaining cost-effective and reliable.

Example Application Domain

The LM324 is widely used in:

• Industrial automation (sensor signal processing, control systems)
• Embedded electronics (line-following robots, measurement systems)
• Audio systems (amplifiers, active filters)
• Medical and scientific instrumentation (weak signal amplification)
• Power supplies and chargers (voltage comparators, regulators)

Example Project

1.5V Battery Tester:

A classic project using the LM324 is a battery tester for AA/AAA cells. The circuit uses the LM324 as a voltage comparator to measure the battery voltage and display the result using LEDs (green, yellow, red) according to the detected level. This tester allows for quick checking of the charge state of both alkaline and rechargeable batteries.

Other project examples:

• LED flasher using op-amps (alternating two LEDs)
• Waveform generator (square or triangle oscillator for PWM or audio)
• Active filter for audio or instrumentation

The LM324 is a key component for many electronic circuits requiring reliability, versatility, and low power consumption.